//----------------------------------------------------------------------------//
//                                                                            //
// ozz-animation is hosted at http://github.com/guillaumeblanc/ozz-animation  //
// and distributed under the MIT License (MIT).                               //
//                                                                            //
// Copyright (c) Guillaume Blanc                                              //
//                                                                            //
// Permission is hereby granted, free of charge, to any person obtaining a    //
// copy of this software and associated documentation files (the "Software"), //
// to deal in the Software without restriction, including without limitation  //
// the rights to use, copy, modify, merge, publish, distribute, sublicense,   //
// and/or sell copies of the Software, and to permit persons to whom the      //
// Software is furnished to do so, subject to the following conditions:       //
//                                                                            //
// The above copyright notice and this permission notice shall be included in //
// all copies or substantial portions of the Software.                        //
//                                                                            //
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR //
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,   //
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL    //
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER //
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING    //
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER        //
// DEALINGS IN THE SOFTWARE.                                                  //
//                                                                            //
//----------------------------------------------------------------------------//
#include "SkrAnim/ozz/base/io/stream.h"

#include <cassert>
#include <cstdio>
#include <cstring>
#include <limits>

#include "SkrAnim/ozz/base/maths/math_ex.h"
#include "SkrAnim/ozz/base/memory/allocator.h"
#include "SkrSerde/bin_serde.hpp"

namespace ozz
{
namespace io
{

// Starts File implementation.

bool File::Exist(const char* _filename)
{
    FILE* file = std::fopen(_filename, "r");
    if (file)
    {
        std::fclose(file);
        return true;
    }
    return false;
}

File::File(const char* _filename, const char* _mode)
    : file_(std::fopen(_filename, _mode))
{
}

File::File(void* _file)
    : file_(_file)
{
}

File::~File() { Close(); }

void File::Close()
{
    if (file_)
    {
        std::FILE* file = reinterpret_cast<std::FILE*>(file_);
        std::fclose(file);
        file_ = nullptr;
    }
}

bool File::opened() const { return file_ != nullptr; }

size_t File::Read(void* _buffer, size_t _size)
{
    std::FILE* file = reinterpret_cast<std::FILE*>(file_);
    return std::fread(_buffer, 1, _size, file);
}

size_t File::Write(const void* _buffer, size_t _size)
{
    std::FILE* file = reinterpret_cast<std::FILE*>(file_);
    return std::fwrite(_buffer, 1, _size, file);
}

int File::Seek(int _offset, Origin _origin)
{
    int origins[] = { SEEK_CUR, SEEK_END, SEEK_SET };
    if (_origin >= static_cast<int>(OZZ_ARRAY_SIZE(origins)))
    {
        return -1;
    }
    std::FILE* file = reinterpret_cast<std::FILE*>(file_);
    return std::fseek(file, _offset, origins[_origin]);
}

int File::Tell() const
{
    std::FILE* file    = reinterpret_cast<std::FILE*>(file_);
    const long current = std::ftell(file);
    return static_cast<int>(current);
}

size_t File::Size() const
{
    std::FILE* file = reinterpret_cast<std::FILE*>(file_);

    const long current = std::ftell(file);
    SKR_ASSERT(current >= 0);
    int seek = std::fseek(file, 0, SEEK_END);
    SKR_ASSERT(seek == 0);
    (void)seek;
    const long end = std::ftell(file);
    SKR_ASSERT(end >= 0);
    seek = std::fseek(file, current, SEEK_SET);
    SKR_ASSERT(seek == 0);

    return static_cast<size_t>(end);
}

// Starts MemoryStream implementation.
const size_t MemoryStream::kBufferSizeIncrement = 16 << 10;
const size_t MemoryStream::kMaxSize             = std::numeric_limits<int>::max();

MemoryStream::MemoryStream()
    : buffer_(nullptr)
    , alloc_size_(0)
    , end_(0)
    , tell_(0)
{
}

MemoryStream::~MemoryStream()
{
    ozz::memory::default_allocator()->Deallocate(buffer_, 16);
    buffer_ = nullptr;
}

bool MemoryStream::opened() const { return true; }

size_t MemoryStream::Read(void* _buffer, size_t _size)
{
    // A read cannot set file position beyond the end of the file.
    // A read cannot exceed the maximum Stream size.
    if (tell_ > end_ || _size > kMaxSize)
    {
        return 0;
    }

    const int read_size = math::Min(end_ - tell_, static_cast<int>(_size));
    std::memcpy(_buffer, buffer_ + tell_, read_size);
    tell_ += read_size;
    return read_size;
}

size_t MemoryStream::Write(const void* _buffer, size_t _size)
{
    if (_size > kMaxSize || tell_ > static_cast<int>(kMaxSize - _size))
    {
        // A write cannot exceed the maximum Stream size.
        return 0;
    }
    if (tell_ > end_)
    {
        // The fseek() function shall allow the file-position indicator to be set
        // beyond the end of existing data in the file. If data is later written at
        // this point, subsequent reads of data in the gap shall return bytes with
        // the value 0 until data is actually written into the gap.
        if (!Resize(tell_))
        {
            return 0;
        }
        // Fills the gap with 0's.
        const size_t gap = tell_ - end_;
        std::memset(buffer_ + end_, 0, gap);
        end_ = tell_;
    }

    const int size     = static_cast<int>(_size);
    const int tell_end = tell_ + size;
    if (Resize(tell_end))
    {
        end_ = math::Max(tell_end, end_);
        std::memcpy(buffer_ + tell_, _buffer, _size);
        tell_ += size;
        return _size;
    }
    return 0;
}

int MemoryStream::Seek(int _offset, Origin _origin)
{
    int origin;
    switch (_origin)
    {
    case kCurrent:
        origin = tell_;
        break;
    case kEnd:
        origin = end_;
        break;
    case kSet:
        origin = 0;
        break;
    default:
        return -1;
    }

    // Exit if seeking before file begin or beyond max file size.
    if (origin < -_offset ||
        (_offset > 0 && origin > static_cast<int>(kMaxSize) - _offset))
    {
        return -1;
    }

    // So tell_ is moved but end_ pointer is not moved until something is later
    // written.
    tell_ = origin + _offset;
    return 0;
}

int MemoryStream::Tell() const { return tell_; }

size_t MemoryStream::Size() const { return static_cast<size_t>(end_); }

bool MemoryStream::Resize(size_t _size)
{
    if (_size > alloc_size_)
    {
        // Resize to the next multiple of kBufferSizeIncrement, requires
        // kBufferSizeIncrement to be a power of 2.
        static_assert(
            (MemoryStream::kBufferSizeIncrement & (kBufferSizeIncrement - 1)) == 0,
            "kBufferSizeIncrement must be a power of 2"
        );
        const size_t new_size   = ozz::Align(_size, kBufferSizeIncrement);
        byte*        new_buffer = reinterpret_cast<byte*>(
            ozz::memory::default_allocator()->Allocate(new_size, 16)
        );
        if (buffer_ != nullptr)
        {
            std::memcpy(new_buffer, buffer_, alloc_size_);
        }
        ozz::memory::default_allocator()->Deallocate(buffer_, 16);
        buffer_     = new_buffer;
        alloc_size_ = new_size;
    }
    return _size == 0 || buffer_ != nullptr;
}

// Starts SkrStream implementation.
SkrStream::SkrStream(SBinaryReader* _reader, SBinaryWriter* _writer)
    : reader_(_reader)
    , writer_(_writer)
{
}

SkrStream::~SkrStream() {}

bool SkrStream::opened() const { return reader_ != nullptr || writer_ != nullptr; }

size_t SkrStream::Read(void* _buffer, size_t _size)
{
    SKR_ASSERT(reader_);
    if (!reader_->read(_buffer, _size))
    {
        return 0;
    }
    return _size;
}

size_t SkrStream::Write(const void* _buffer, size_t _size)
{
    SKR_ASSERT(writer_);
    if (!writer_->write(_buffer, _size))
    {
        return 0;
    }
    return _size;
}

int SkrStream::Seek(int _offset, Origin _origin)
{
    SKR_UNIMPLEMENTED_FUNCTION()
    return 0;
}

int SkrStream::Tell() const
{
    SKR_UNIMPLEMENTED_FUNCTION()
    return 0;
}

size_t SkrStream::Size() const
{
    SKR_UNIMPLEMENTED_FUNCTION()
    return 0;
}

} // namespace io
} // namespace ozz
